RC Engineering is a reputable company that cleans and flow tests fuel injectors off the motor.
I read a lot about Ford dealerships recommending a FI cleaning with them on the motor (I suppose by attaching cleaner to the fuel rail somehow). But I suspect that most of the time this is just a quick money grab. A local guy flunked a smog test, then passed after new plugs and wires, and
then the dealer pushed for the FI cleaning "so he can pass smog". He declined and then realized that they were trying to be less than clear with the fact that he had already passed the test. I don't think he goes back there any more.
As far as gas tank FI cleaners, Chevron Techtron and Redline Complete Fuel System Cleaner are the best brands to use IMHO (I prefer Redline personally).